Fish oil supplements do not prevent heart attacks or strokes in patients with diabetes, a new study has found.

In observational studies, higher consumption of fish is associated with lower risks of coronary artery disease and stroke. However, previous trials have not been able to show that taking fish oil supplements containing omega-3 fatty acids reduce the risk of having cardiovascular events.

The ASCEND trial (A Study of Cardiovascular Events in Diabetes) examined whether fish oil supplements reduce the risk of a cardiovascular event in patients with diabetes. The primary efficacy outcome was the first serious vascular event, which included non-fatal heart attacks, non-fatal strokes or transient ischemic attacks (sometimes called "mini-strokes"), or deaths from a cardiovascular cause.

Principal investigator, Dr. Louise Bowman, said, "Our large, long-term randomised trial shows that fish oil supplements do not reduce the risk of cardiovascular events in patients with diabetes. This is a disappointing finding, but it is in line with previous randomised trials in other types of patient at increased risk of cardiovascular events which also showed no benefit of fish oil supplements."

"There is no justification for recommending fish oil supplements to protect against cardiovascular events," he added. The full findings are present in the journal- New England Journal of Medicine.